1. Field of the Invention
The present invention relates to an insulator. More particularly, the present invention relates to an insulator for a trailing arm bushing, an engine mounting bushing, a transmission mounting busing and so on.
2. Description of Related Art
Basically, a suspension system refers to the use of front and rear springs to suspend a vehicle's frame and body, or unitized body, as well as the engine and power train above the wheels.
The suspension system is mainly divided into a rigid axle suspension and an independent suspension, and recently the independent suspension has been primarily used for a passenger car.
In the independent suspension system, a rear suspension system of a coupled torsion beam axle (CTBA) type has a simple structure, a low manufacturing cost, and a low weight, and the rear suspension system of the coupled torsion beam axle has reliable driving stability so it is broadly used for a small car or a small sedan.
The rear suspension system of coupled torsion beam axle type, as shown in FIG. 14, includes a torsion beam 101 that is disposed along a width direction of a vehicle, and a trailing arm 105 that is provided with a carrier 103 for mounting a tire and a wheel.
A bushing unit 109 and a shock absorber 107, which is connected with a frame of a vehicle, are disposed forward and rearward of the trailing arm 105, and a spring 113 is disposed to a spring seat 111.
The bushing unit 109 includes a bushing 121 and a bushing bracket 125.
The bushing 121 includes an outer pipe 115 that is connected to an end of the trailing arm 105, an inner pipe 117 that is disposed within the outer pipe 115, and an insulator 119 that is disposed between the outer pipe 115 and the inner pipe 117.
The bushing 121 is mounted to the bushing bracket 125, which is mounted to a subframe, by a bolt 123 that penetrates the inner pipe 117.
A center hole 126, in which the inner pipe 117 is mounted, is formed to the insulator 119, as shown in FIG. 14 and FIG. 15, and a pair of operation slots 127 is formed near the center hole 126.
The shape of each operation slot 127 is as a curved line symmetrically formed with respect to the center hole 126, wherein ends of the operation slots 127 are bent toward the circumference of the insulator 119.
However, the conventional insulator is subject to contact with a vehicle body when a vehicle is driving, and if the contact continues, a crack can be generated in the insulator, particularly in the end of the insulator.
Enlargement of the crack may induce deterioration of ride comfort, driving stability, durability, and so on.
Also, bushings for mounting other elements for a vehicle have similar problems.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.